Nuclear magnetic resonance (NMR) has had its experimental technical fundamentals established conjointly with the rapid progress of electronic engineering in the past several decades, and has been applied to various research related to atoms, molecules, liquids, and solids. Especially in the fields of solid state physics and chemistry, NMR is an unequalled effective research means in the sense that materials can be understood from the microscopic point of view. NMR is a specific aspect of radio wave spectroscopy involving the use of only a uniform static magnetic field and a weak RF magnetic field for interaction with a measuring system.
Recently, research has been performed on the clinical application of NMR, i.e., tomography which employs the technology of NMR and image processing technology well known in X-ray CT (NMR Computerized Tomography: NMR-CT).
For the purpose of NMR observation, as illustrated in FIG. 1, a highly uniform static field H.sub.O (0.15 tesla at the highest) is generated by four solenoid coils or main coils MC1 through MC4 which are concentrically arranged in the form of a cylinder. Inserted inside the air-core coils is a Golay coil GC for a gradient field, which generates linear gradient fields along x-, y- and z-axes when the direction of the static field H.sub.o is assumed to coincide with that of the z-axis. Further, a saddle-shaped RF or high frequency coil SC which applies an RF magnetic field H.sub.1 which is uniform in a wide range and in a direction orthogonal to the static magnetic field H.sub.o and with which an NMR signal can be observed is arranged inside the Golay coil GC.
Heretofore, the high frequency coil for NMR-CT of the type specified above has been as shown in FIG. 2. Referring to the figure, numeral 1 designates a copper tube which constitutes the high frequency coil, numeral 2 designates electrodes which are unitary with the copper tube 1 and which supply an RF current, and numeral 3 designates an RF magnetic field which results from the RF current caused to flow through the high frequency coil.
Since the conventional high-frequency coil for NMR is constructed as described above, it is necessary to bend the copper tube in accordance with predetermined dimensions, and it is not very easy to fabricate the copper tube with a predetermined accuracy.